Grounding clamp for armored conductors



Oct. 9, 1962 R. F. PIASECKI 3,058,087

GROUNDING CLAMP FOR ARMORED CONDUCTORS Filed Dec. 2, 1960 INVENTORZflay/2200a 4 Pz'aseckz @dww 9" 3,058,087 Patented Oct. 9, 1962 FiledDec. 2, 1960, Ser. No. 73,290 1 Claim. (Cl. 339-95) The inventionrelates to ground clamps for electrical conductors and more particularlyto a saddle clamp adapted for grounding a bare end portion of an armoredmulti-strand or an armored solid copper conductor to a copper water pipeor the like.

More specifically, the invention relates to a ground clamp of thecharacter described which comprises a pair of similar sheet metalstampings each having an intermediate portion of substantially Vconfiguration and including a machine screw threaded through each end ofthe clamp whereby the said stampings are adapted to embrace a water pipeand to be secured thereon by said screws, one of said stampingsincluding means for securing the bare end portion of an armored groundconductor therebetween, means for compensating for the differencebetween the outer diameter of the ground conductor and the outerdiameter of its armor, and means for securing the armor of saidconductor against endwise movement relative to said ground clamp andsaid conductor.

As known heretofore, ground clamps of this character possessed certaindisadvantages in that they were not adapted for securing a bare endportion of an armored ground conductor to and between one of such clampsand a water pipe, while compensating for the diflerence in the diameterof the conductor and the outer diameter of the armor thereon, nor forsecuring the armor against endwise movement relative to the groundconductor and the ground clamp.

The present invention obviates the above noted disadvantages byproviding a ground clamp wherein means are provided integral therewithfor receiving a bare end portion of a ground conductor and the adjacentend portion of the armor thereon in pre-determined relation therewithupon securing the ground clamp about a water pipe or the like.

Accordingly, it is an object of the invention to provide an improvedgrounding clamp for use with armored ground conductors which obviatesthe aforesaid disadvantages.

Another object of the invention is the provision of a ground clamp asspecified, wherein a bare end portion of an armored ground conductor issecured to and between one half section of the clamp and a water pipe orthe like upon securing the clamp thereon.

A further object of the invention is the provision of a ground clamp asspecified wherein a first means struck out of the plane of one of theclamp sections, compensates for the difference between the diameter ofthe ground conductor per se and the outer diameter of the adjacent endportion of the armor enclosing the same.

Another object of the invention is the provision of a ground clamp asspecified wherein a second means struck out of the plane of theaforesaid section of the two part clamp, in spaced axial alignment withthe aforesaid first means, is adapted to seat between the spiralconvolutions of the armor on the grounding conductor to prevent endwisemovement of the armor relative to the clamp members and the groundconductor.

A further object of the invention is the provision of a ground clamp asspecified wherein means integral with one half section of the clamp isoperable to automatically secure a bare end portion of an armored groundconductor and the adjacent end portion of the armor thereon to andbetween the clamp and a water pipe or the like upon securing the clampon said water pipe.

Various other objects, advantages and features of the invention willbecome apparent from the following detailed description when read inconnection with the accompanying drawing, in which:

FIGURE 1, is a plan view showing a grounding clamp and associatedarmored ground conductor as secured on a copper water pipe or the like;

FIGURE 2 is an end view of the same;

FIGURE 3 is a side elevation of the grounding clamp and associatedarmored ground conductor as assembled and secured on a copper water pipeor the like;

FIGURE 4 is a fragmentary elevational view showing the ground clamp incross-section to illustrate the manner in which a bare end portion of anarmored ground conductor and the adjacent end portion of the armorthereon is secured to and between the clamp and a copper water pipe orthe like;

FIGURE 5 is a perspective view of one half section of the ground clampwhich incorporates the integral means for securing the bare end portionof a ground conductor and the adjacent end portion of the armor thereon;and

FIGURE 6 is a longitudinal sectional view of the clamp section shown inFIGURE 5.

Referring to the drawing, the grounding clamp, generally indicated at10, comprises a pair of elongated, rectangular sheet metal stampings 12and 14, of brass for example, each stamping having oppositely inclinedsurfaces '16, of V-for-m centrally thereof throughout its width, and itsparallel side margins 18, flanged normal thereto for imparting rigiditythereto.

The stamping 12 is provided with a clearance opening 20, adjacent eachend thereof, and the stamping 14 with an aligned screw threaded opening22, adjacent each end thereof for the reception of a pair of machinescrews 24, for adjustably connecting the respective stampings 12 and 14,whereby they are adapted to be secured about a copper water pipe 26, orthe like.

As clearly shown in FIGURES 1 through 4, the function of the groundclamp 10, is to secure an armored grounding conductor 28, in approvedelectrical contact with the copper water pipe 26. .For this purpose, thestamping 12, as best shown in FIGURE 5, is provided with an arcuatetongue 30 which is struck out of the plane thereof across the root ofits oppositely inclined surfaces 16, and arched inwardly centrally ofsaid surfaces 16, with its severed free end 32, remaining in the slot34, which free end resulted from the striking out of the tongue St), toprovide a loop for the passage therethrough of a bare end portion 36 ofthe armored ground conductor 28. To compensate for the difference indiameter between the bare end portion 36 of the ground conductor 28, andits spiral armor 28, a transverse protuberance or projection 40, isformed integral with the upper face of the arcuate tongue 30, centrallythereof for a purpose hereinafter described.

The stamping 12, 'as best shown in FIGURE 5, is also provided withprotuberance or projection 42, struck out of the plane of itsV-forrnation 16, across the root thereof, in laterally spaced relationto the arched tongue 30, and at an angle corresponding to the pitch ofthe spiral convolutions of the armor on the ground conductor 28, wherebythe projection 42, is adapted to seat between the convolutions of thespiral armor 38, as best shown in FIG- URES 1 and 4, to prevent endwisemovement thereof relative to the stamping 12, and ground conductor 36,after the ground clamp 10, with the armored ground conductor 28,properly positioned therein, has been secured about the copper waterpipe 26.

From a consideration of FIGURES 2 and 4, it will be readily apparentthat in securing the clamp 10, with the armored ground conductor 28,properly inserted therebetween, the final adjustment of the screws 24,forces the arched tongue 30, into intimate bearing engagement with thebare end portion of the ground conductor 36, and end 36 into intimatebearing engagement with the stamping 12, at the root 'of its V-surfaces16, whereby an approved ground connection is made with the copper waterpipe 26, or the like.

As shown in FIGURE 5, the inner faces of the intermediate V-surfaces ofthe stamping 12, are provided with a plurality of parallel linearserrations or score markings 44, to provide roughened surfaces adaptedto substantially bite into the periphery of the copper water pipe 26,about which the clamp 10, is secured for the purposes set forth.

While the invention has been illustrated and described with respect to apreferred embodiment thereof, it is to be expressly understood thatvarious changes and modifications may be made therein without departingfrom the inventive concept underlying the same. Therefore, the inventionis not to be limited except as is necessitated by the prior art and thescope of the appended claim.

What is claimed is:

A saddle clamp for grounding an armored conductor on a cylindricalconduit comprising a pair of flanged sheet metal stampings, a pair ofmachine screws adjustably connecting said stampings at their respectiveend portions, each of said stampings having a pair of oppositelyinclined surfaces formed centrally thereof provided with spaced,parallel linear scorings lengthwise thereof whereby said stampings areadapted to substantially embrace a cylindrical conduit in bitingengagement therewith, an arcuate tongue struck out of the plane of oneof said stampings centrally of and at the base of its inclined surfacesfor receiving a bare end portion of an armored ground conductortherethrough, and a rounded protuberance raised out of the plane of saidone stamping in spaced alignment with said arcuate tongue and at anangle thereto corresponding to the pitch of the spiral armor of saidground conductor, said tongue and said protuberance being adaptedrespectively to clamp said bare conductor end portion to said onestamping and to secure the spiral armor of said ground conductor againstendwise movement relative to said one stamping upon securing said clampon said cylindrical conduit, and a transverse substantially rectangularprojection integral with said arcuate tongue centrally of its outerperiphery adapted to compensate for the dilference between the diameterof the bare end portion of said ground conductor and the outer diameterof its spiral armor.

References Cited in the file of this patent UNITED STATES PATENTS1,914,010 Eccles June 13, 1933 2,490,253 Buchanan Dec. 6, 1949 2,533,897Reddock Dec. 12, 1950 FOREIGN PATENTS 23,579/29 Australia May 28, 1930528,644 Canada Aug. 7, 1956

